• addEventListener + removeEventListener

    tl;dr: Avoid memory leaks by ensuring that if you register a callback to addEventListener you also unregister it with removeEventListener later on.

  • structuredClone

    tl;dr: To deep clone objects, Use structuredClone(value) rather than the JSON.parse(JSON.stringify(value)) trick. Also, avoid Lodash’s _.cloneDeep(value) due to import cost.

  • requestAnimationFrame + setTimeout

    tl;dr: This is how you correctly measure performance after style, layout, and paint operations.

  • V8 Flags

    tl;dr: A printout of all Chromium V8 flags. Some are useful for debugging.

  • HTTP/2

    tl;dr: Avoid HTTP/1.1 because browsers limit the number of concurrent requests going to HTTP/1.1 origins. Use HTTP/2.

  • performance

    tl;dr: Avoid using Date to measure durations. Use the performance interface to measure durations because of its high precision.

  • Intl

    tl;dr: Use Intl to compute relative dates, rather than rely on Luxon or Moment which are huge size-wise.

  • Lazy Loading

    tl;dr: Use loading="lazy" to defer loading images that are off-screen until the user scrolls near them.

  • SVG Minification

    tl;dr: Use svgo to minify SVGs.

  • Brotli

    tl;dr: Compress assets such as JavaScript and CSS using Brotli rather than gzip.